1. Field of the Invention
The present invention relates to solvent composition comprising dichloropentafluoropropane and (perfluorobutyl) methyl ether.
2. Discussion of Background
Dichloropentafluoropropane (hereinafter referred to simply as R225), 1,1-dichloro-1-fluoroethane (hereinafter referred to simply as R141b), or a solvent mixture composition of R225 or R141b with a solvent soluble therein, which is excellent in non-flammability, low toxicity and stability, has been widely used for various degreasing, defluxing or dust removal, or as a dewatering solvent, a dry cleaning solvent, a solvent for chemical reaction, a carrier solvent for silicone and halogenated lubricants or the like. Further, (perfluorobutyl) methyl ether has been developed and is being marketed.
R225 or a solvent mixture composition of R225 with a solvent soluble in R225, is used for various degreasing and defluxing. However, R225 adversely affects an acrylic resin, and could not be used for cleaning a part containing this resin.
(Perfluorobutyl) methyl ether scarcely affects a resin, but its solvency of e.g. oil is poor, whereby the cleaning ability tends to be inadequate, and no adequate cleaning effects can be obtained.
WO-96/36689 discloses an azeotropic composition comprising from 61 to 90 wt % of R225 and from 10 to 39 wt % of (perfluorobutyl) methyl ether. However, this composition was found to be ineffective for overcoming the adverse effect of R225 against the acrylic resin.